Which of the following would be an INAPPROPRIATE activity for a network administrator?
Correct Answer: D
Section: Information System Operations, Maintenance and Support
Question 92
An auditor needs to be aware of technical controls which are used to protect computer from malware. Which of the following technical control interrupts DoS and ROM BIOS call and look for malware like action?
Correct Answer: B
Explanation/Reference: Active monitors interpret DoS and read-only memory (ROM) BIOS calls, looking for malware like actions. Active monitors can be problematic because they can not distinguish between a user request and a program or a malware request. As a result, users are asked to confirm actions, including formatting a disk or deleting a file or set of files. For CISA exam you should know below mentioned different kinds of malware Controls A. Scanners Look for sequences of bit called signature that are typical malware programs. The two primary types of scanner are 1. Malware mask or Signatures - Anti-malware scanners check files, sectors and system memory for known and new (unknown to scanner) malware, on the basis of malware masks or signatures. Malware masks or signature are specific code strings that are recognized as belonging to malware. For polymorphic malware, the scanner sometimes has algorithms that check for all possible combinations of a signature that could exist in an infected file. 2. Heuristic Scanner - Analyzes the instructions in the code being scanned and decide on the basis of statistical probabilities whether it could contain malicious code. Heuristic scanning result could indicate that malware may be present, that is possibly infected. Heuristic scanner tend to generate a high level false positive errors (they indicate that malware may be present when, in fact, no malware is present). Scanners examines memory disk- boot sector, executables, data files, and command files for bit pattern that match a known malware. Scanners, therefore, need to be updated periodically to remain effective. B. Immunizers - Defend against malware by appending sections of themselves to files - sometime in the same way Malware append themselves. Immunizers continuously check a file for changes and report changes as possible malware behavior. Other type of Immunizers are focused to a specific malware and work by giving the malware the impression that the malware has already infected to the computer. This method is not always practical since it is not possible to immunize file against all known malware. C. Behavior Blocker- Focus on detecting potential abnormal behavior such as writing to the boot sector or the master boot record, or making changes to executable files. Blockers can potentially detect malware at an early stage. Most hardware based anti-malware mechanism are based on this concept. D. Integrity CRC checker- Compute a binary number on a known malware free program that is then stored in a database file. The number is called Cyclic Redundancy Check (CRC). On subsequent scans, when that program is called to execute, it checks for changes to the file as compare to the database and report possible infection if changes have occurred. A match means no infection; a mismatch means change in the program has occurred. A change in the program could mean malware within it. These scanners are effective in detecting infection; however, they can do so only after infection has occurred. Also, a CRC checker can only detect subsequent changes to files, because they assume files are malware free in the first place. Therefore, they are ineffective against new files that are malware infected and that are not recorded in the database. Integrity checker take advantage of the fact that executable programs and boot sectors do not change often, if at all. The following were incorrect answers: Scanners -Look for sequences of bit called signature that are typical malware programs. Immunizers - Defend against malware by appending sections of themselves to files - sometime in the same way Malware append themselves. Immunizers continuously check a file for changes and report changes as possible malware behavior. Behavior Blocker- Focus on detecting potential abnormal behavior such as writing to the boot sector or the master boot record, or making changes to executable files. Blockers can potentially detect malware at an early stage. Most hardware based anti-malware mechanism are based on this concept. The following reference(s) were/was used to create this question: CISA review manual 2014 Page number 354 and 355
Question 93
An IS auditor finds the log management system is overwhelmed with false positive alerts. The auditor's BEST recommendation would be to:
Correct Answer: D
Section: Protection of Information Assets
Question 94
Following a recent internal data breach, an IS auditor was asked to evaluate information security practices within the organization. Which of the following findings would be MOST important to report to senior management?
Correct Answer: B
Question 95
An integrated test facility is not considered a useful audit tool because it cannot compare processing output with independently calculated datA. True or false?
Correct Answer: B
Explanation/Reference: An integrated test facility is considered a useful audit tool because it compares processing output with independently calculated datA.
